Felting needle

ABSTRACT

A felting needle constructed in the form of an elongated body having a shank portion and a barbed portion. The barbed portion has a plurality of barbs and terminates in a pointed end. A Vshaped or U-shaped circumferential indentation is provided somewhere along the length of the shank portion to define the weakest structural location along the length of the elongated body, which is called the fracture point.

United States Patent lnventor Appl. No. Filed Patented FELTING NEEDLE 9 Clalms, 9 Drawing Figs.

U.S. C1 28/4 N Int. Cl..... D04h 18/00 Fleld of Search 28/4 N;

[56] References Cited UNITED STATES PATENTS 2,327,416 8/1943 Foster 28/4 N 3,353,243 11/1967 Foster 28/4 N Primary Examiner- Louis K. Rimrodt Attorney-Johnson. Dienner, Emrich. Verheck and Wagner ABSTRACT: A felting needle constructed in the form of an elongated body having a shank portion and a barbed portion. The barbed portion has a plurality of barbs and terminates in a pointed end. A V-shaped or U-shaped circumferential indentation is provided somewhere along the length of the shank portion to define the weakest structural location along the length of the elongated body, which is called the fracture point.

FEL'IING NEEDLE BACKGROUND OF THE INVENTION My present invention relates to improvements in felting needles.

In commercial felting machines, a needle board or plates carrying a large number of needles is reciprocated at a large rate to drive the needles into a fibrous material to cause interlacing and compacting of the loose fibrous material. A typical needle loom would drive a needle board having 12,000 needles at a reciprocation rate of 600 r.p.m. If during the machines operation one or more of these needles become bent or broken at a point in the barbed section where the stud end of the needle continued to contact the material it will mark the surface and leave streaks which make the fabric unmarketable. Furthermore, it is necessary that the felting machine be stopped so that the defective needles can be replaced.

SUMMARY OF THE INVENTION This invention relates to an improved construction which eliminates damage caused by a bent or broken needle.-

The principle of the invention is to form a localized stress or fracture point in a felting needle located above the barbed portion, at which point the needle will always break when subjected to a greater than normal strain.

The fracture point should preferably be located in substantially a single plain cross section of the needle body portion. It would be located in the needle body portion above the barbed portion a distance so that in operation the fracture point never would penetrate the needle fabric.

The fracture point can be specified as to extent and characteristics. These are determined exactly by the degree of fracture potential desired in a particular needle application.

Basically the fracture point is a series or one or more notches or a continuous circumferential groove around the needle body. The notch or groove would be V-shaped for high-fracture potential. They would be U-shaped for a tougher more moderate fracture potential.

Generally needles with finer gauge blades or barbed portions which are very flexible require a higher fracture potential. More rugged coarse gauge blades with barbed portion which are stiffer require the tougher fracture potential.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of this invention reference should be made to the accompanying drawing, in which:

FIG. 1 is an elevational view of a felting needle illustrating the first embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along the line 2-2 of FIG. 1;

FIG. 3 is an enlarged partial side view of FIG. 1 illustrating a V-shaped indentation.

FIG. 4 is an enlarged partial side view of a second embodiment of this invention;

FIG. 5 is a cross-sectional view taken along the line 55 of FIG. 4;

FIG. 6 is an enlarged partial view of a third embodiment of this invention;

FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG. 6; and

FIGS. 8 and 9 are, respectively. enlarged partial views of the third and fourth embodiments ofthis invention.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIG. I, there is shown a felting needle incorporating the principles of my invention which comprises an elongated body 10 having a barbed portion 12 and a shank portion 16.

The upper end I8 of the shank portion 16 is bent at a 90 angle relative to the rest of the needle 10 for clamping between a base member and a clamping member ofa conventional needle board. As already mentioned, a felting needle board is adapted to carry a large number of felting needles in the order of I2,000 needles.

The barbed portion 12 terminates into a point 20 at its lower end to facilitate penetration of the fibrous material to be compacted. A plurality of barbs 22, which may be of any desired size and configuration, are formed along the length of barbed portion 12.

Felting needles constructed in accordance with the principles of my invention may be made of any ordinary or conventional needle stock having the necessary mechanical strength, for example. steel wire. The felting needle of my invention could be readily formed from round steel wire stock from which a suitable length is cut to provide an elongated body portion.

The novelty of this invention resides in adding to a felting needle a fracture point somewhere between the upper end 18 of the needle and the barbed portion I2. In the first embodiments (FIGS. 1-3), the fracture point 24 is located approximately midway along shank portion 16. As depicted in FIGS. 2 and 3, the fracture point 24 is formed by two diagonally opposite V-shaped indentations or notches 28. The sides 30 of notches 28 diverge outwardly at an approximate 60 angle.

The fracture point 24 is defined as the weakest structural position along the length of felting needle 10, which will break upon the transmittal of any significant resistive force exerted against the barbed portion as the felting needle is driven vertically downward. Consequently, if one of the needles in a needle board becomes bent during a needling operation, the barbed 'portion of the needle will strike the stripper plate as it is driven downward and cause the needle 10 to break at fracture point 24. The bent needle will break off before it penetrates the fibrous material below the stripper plate and thereby avoid damaging the material.

The loss of one or more needles from a needle board carrying thousands during the needle punching will not noticeably affect the resulting product. The broken off portions can be readily picked up by using a magnetic device.

SECOND EMBODIMENT Referring to FIGS. 4 and 5, there is shown a second manner of providing a fracture point somewhere in the shank portion of a felting needle comprising four V-shaped notches 50 equally spaced about the circumference of the shank portion. The V-shaped notch provides a high-fracture potential and would be used with the finer gauge needles due to their inherent large flexibility.

THIRD EMBODIMENT Referring to FIGS. 6 and 7, there is depicted another frac- FOURTH AND FIFTH EMBODIMENTS There is shown in FIGS. 8 and 9, two additional fracture point means for a felting needle. Their location could be anywhere along the shank portion at a distance above the barbed portion to prevent the fracture point from penetrating the needle fabric.

In FIG. 8 the fracture point means comprises a single V- shaped indentation 56. Similarly in FIG. 9, the fracture point means comprises a single U-shaped indentation 58.

From the foregoing description of five embodiments it can be seen that the principle of my invention can be utilized in a large variety of ways. All that is necessary is to form a localized stress or fracture point somewhere along the length of a felting needles shank portion at a distance above the barbed portion so that the fracture point would never penetrate the needle fabric during operation of the felting machine.

While there has been shown and described preferred embodiments of the invention, it will be understood that various other body cross-sectional configurations may be employed.

1 claim:

l. A felting needle constructed as an elongated body having a pointed end and at least one barb adjacent said pointed end, the improvement comprising a fracture point means between the other end of said elongated body and said at least one barb for providing the weakest structural location along the length of said elongated body, whereby any significant impact stress exerted against said pointed end will cause said elongated body to break off at said weakest structural location.

2. A felting needle as defined in claim 1, wherein said fracturepoint-means includes a pair of diametrically opposite V- shaped indentations.

3. A felting needle as defined in claim 1, wherein said fracture point means comprises a continuous circumferential groove formed transversely to the longitudinal axis of said elongated body. 1

4. A felting needle as defined in claim 3. wherein said circumferential groove is U-shaped.

5. A felting needle as defined in claim 1, wherein said fracture point means includes at least one notch formed transversely to the longitudinal axis of said elongated body.

6. A felting needle as defined in claim 5, wherein said at least one notch is V-shaped.

7. A felting needle as defined in claim 5, wherein said needle is U-shaped.

8. A felting needle as defined in claim 1, wherein said fracture point means comprises four equally spaced notches around the circumference of said elongated body.

9. A felting needle as defined in claim 8, wherein said four equally spaced notches are V-shaped. 

1. A felting needle constructed as an elongated body having a pointed end and at least one barb adjacent said pointed end, the improvement comprising a fracture point means between the other end of said elongated body and said at least one barb for providing the weakest structural location along the length of said elongated body, whereby any significant impact stress exerted against said pointed end will cause said elongated body to break off at said weakest structural location.
 2. A felting needle as defined in claim 1, wherein said fracture point means includes a pair of diametrically opposite V-shaped indentations.
 3. A felting needle as defined in claim 1, wherein said fracture point means comprises a continuous circumferential groove formed transversely to the longitudinal axis of said elongated body.
 4. A felting needle as defined in claim 3, wherein said circumferential groove is U-shaped.
 5. A felting needle as defined in claim 1, wherein said fracture point means includes at least one notch formed transversely to the longitudinal axis of said elongated body.
 6. A felting needle as defined in claim 5, wherein said at least one notch is V-shaped.
 7. A felting needle as defined in claim 5, wherein said needle is U-shaped.
 8. A felting needle as defined in claim 1, wherein said fracture point means comprises four equally spaced notches around the circumference of said elongated body.
 9. A felting needle as defined in claim 8, wherein said four equally spaced notches are V-shaped. 